I finally made my first 50mpg tank with normal driving (not all freeway)!

So I was hoping I would be able to do it again, but it got pretty hot in southern California this weekend (I can usually stand it, but my girlfriend needs the AC). Not only can I not hit the 50 mpg mark, but I'm struggling just to maintain 44 mpg. I set the climate control to Auto at 70. My best tank before the last one was about 48 mpg, so a loss of 4 mpg isn't bad to stay cool, but is it possible to keep up the FE when the temperature gets hot?!?

Thanks

 

Setting the climate control to 70 is not the best approach. Instead, do the following:
- Before starting the car open the windows and doors.
- Start driving the car with the windows open
- A minute later close the windows and set the temp control 82F or higher.
- As soon as you hear the climate control fan slowing down, lower the temperature by 1 degree. Continue to do so until everyone feels comfortable. You'll notice that comfort can be achieved at a higher temp than 70.

Now, what does all of this do?
It helps to ensure that the AC runs completely on electric. If you set the temperature to too low the belt driven half of the hybrid compressor will run as well and that will really KILL your FE. However, running on electric means that you'll still get penalized but not by nearly as much as running it full throttle.

Also, if you improve your pack management skills you'll notice that running AC in the summer will have minimal impact on your FE.



Cheers;

MSantos

 

Msantos,
Thanks for the advise. Very good point about opening the windows. I must try this, as everything else I do. Thanks,H

 

Agreed with MS.

The 1st stage of AC takes away very little FE. When it gets really hot and the 2nd stage kicks in, FE seriously suffers.

FWIW, I keep mine on 78 and then adjust with the fan speed.

Cheers, nf

 

A few weeks ago I went out to get lunch and sat in the parking lot while I ate. It was our first warm day, about 88 degrees. During the 15 minutes I sat with the car in park with the engine on and the air on low, my avg mpg went down by 3.2 mpg. My tank was at about 3/4 so I had just reset the gauge 2 days prior, but I was shocked by the fe decline. Since then I have put the windows down and haven't used the air at all. I hope to do this as much as possible.

 

Not enough for me to leave it off. Ever. A cracked window will hurt it much more than the a/c. Not to mention the pollutants from the non-green cars out there. get 43-46 regardless of where I run, and we go to the mountains every weekend. What you lose going up, you gain coming down.

 

I don't agree on the windows. That MIGHT be true at highway speeds, but your windows being open have a very negligable effect at sub 60mph speeds. I find that using the AC in town has a noticable effect since it seems to inhibit glide.

Personally, I think mountains are very good for the HCHII--I consider them a "forced" pulse and glide. If your able to go up at 30mpg and down at 0gmp, that works out to a fantastic average!

 

Incorrect. This was studied and disproven on Mythbusters. They took 2 identical vehicles, ran one with all windows completely down and one with the air conditioning on medium. Both vehicles contained the same exact amount of gas and were ran at the same speeds, during the same time and same conditions, on a track. The vehicle running the air conditioning ran out of gas many laps before the vehicle with the windows down. I wish the opposite were true because I'd rather use the air conditioning since I have allergies.

 

I run on Auto at 80 when it hits 100 and above. My FE is still over 50mpg. I'm happy and I think the pack is too? H

 

Roll down just the back windows and ride then. Listen to the turbulence. That is effecting your fuel mileage. Physics 101. Plus, even though I am a tightwad on gas, I wouldn't ride without the a/c in the heat. Friends will think you cut back on buying soap also.